Thus for example electronic purses are already known in the field of chip cards, or more generally portable equipment with a computer chip. In such uses monetary units stored in the memory of a chip card are transferred to another and withdrawn from the first. There is on the face of it no limit to validity. Also in the banking sector chip cards, the card body of which is clearly embossed with the expiry date of the card, are known. This precaution of limiting the validity of the card has two objectives. On the one hand it allows the age of the electronic circuits to be taken into account and to facilitate its replacement. On the other hand it gives rise to the return of the cards in circulation to the supervisory body in such a way that this body can totally control the means which it makes available to carry out transactions.
With the exponential development of applications controlled by uses of the chip card, expired chip cards may no longer need to be replaced by a supervisory body: it ought to be possible to do this on site, if necessary with common chip card readers/recorders.
The principles of using chip cards include the requirement to compose a secret code or personal identity number (PIN) and comparison of this code with a code stored in the memory of the chip. If this comparison is successful, the application i.e. in practical terms goods or services corresponding to the transaction can be obtained, or even a payment can be effected with the card. If not the case a reject situation is indicated to the carrier. This comparison is implemented in a fail-safe manner.
The problem which occurs when the requirement is to transfer data from one card to another is a problem of managing these secret codes or, more generally, management codes which allow management under the control of data stored in the memory of the cards. In fact these codes stored in one form or another in the memory of the chip card are produced by the supervisory body according to data capable of identifying the card and particular to this body. As a result it is impossible to arrange the automatic extension of the validity of the cards by replacing expired cards with cards with longer memory without the intervention of this body. Indeed such an operation would amount to disclosing all the secrets concerning the formulation of the secret codes and particular to this body to all the other organizations or even all the readers capable of arranging this extension.
However the aim of the invention is to remedy this future problem by instituting a recording procedure for the management codes. The procedure takes into account the previous management codes or at least data relating to the old cards from which the data are to be recorded into the new originates.